[0001] The invention relates to a television receiver comprising a circuit for sequentially
tuning the receiver to different frequencies and displaying a composite picture comprising
a group of sub-pictures which correspond to pictures transmitted by transmitters received
at the said different frequencies, the receiver comprising a memory circuit for storing
sub-picture information.
[0002] DT-AS 2 413 839 discloses the possibility to obtain such a television receiver.
[0003] Further to this citation, the US Patent Specification 4 259 690 and Radio Mentor
Electronic, Vol. 48, No. 8, August 1977, p. 334 describe television receivers with
moving sub-pictures.
[0004] The invention has for its object to provide an advantageous construction of a television
receiver as described in the opening paragraph.
[0005] According to the invention, a television receiver of the type described in the opening
paragraph, is characterized in that the receiver comprises a second memory circuit
which is capable of being coupled to the first-mentioned memory circuit for acquiring
from the first-mentioned memory circuit the sub-picture information from a group of
transmissions, which sub-picture information is obtained during the sequential tuning
operation, and for displaying the group of sub-pictures associated with the group
of transmissions in such a way from the second memory circuit that with a further
sequential tuning of the receiver to different frequencies these groups of sub-pictures
in a composite picture can simultaneously change their picture content so that a survey
of still sub-pictures is obtained.
[0006] As a result thereof, a television receiver in accordance with the invention provides
a composite picture which gives a restful impression of a survey of still pictures
of receivable programs.
[0007] The invention will now be further described by way of example with reference to the
drawing which comprises only one Figure.
[0008] The Figure illustrates by means of a concise block diagram a television receiver
in accordance with the invention.
[0009] The tuning of a receiving portion 1 is periodically, for example after every 300
msec., changed to a different frequency in response to a signal combination received
from an output combination 5 of a synchronizing circuit 7 and applied to an input
combination 3. This is effected, for example, nine times, whereafter this tuning cycle
is repeated.
[0010] Some time after the tuning has been changed the control sections in the receiving
portion 1 have settled and a video signal appears at an output 9, a horizontal synchronizing
signal at an output 11, and at an output 13 a vertical synchronizing signal from a
transmission which is received at the frequency the receiver is tuned to. The synchronizing
signals are applied to two inputs 15 and 17 of the synchronizing circuit 7.
[0011] In addition, the horizontal synchronizing signal is applied to a frequency and phase
detector 19, to which also a signal coming from an output 23 of a first pulse generator
25 is applied via a frequency divider 21. The frequency and phase detector 19 applies
a control signal to a control signal input 26 of the first pulse generator 25, in
response to which the pulse generator 25 is synchronized with the horizontal synchronizing
signal.
[0012] The output 23 of the first pulse generator 25 is further connected to a counting
signal input of a first counting circuit 27, an output combination of which is connected
to an input combination 29 of the synchronizing circuit 7.
[0013] The first counting circuit 27 applies to the input combination 29 of the synchronizing
circuit 7 information about the position of the picture element from which corresponding
video information is received at that moment.
[0014] An input combination 31 of the synchronizing circuit 7 receives from a second counting
circuit 33, whose counting signal input is connected to an output 35 of a change-over
circuit 37 and to a clock signal input 39 of a first memory circuit 41, information
about the position in the first memory circuit 41 of a signal combination of a video
signal sample which must be written into or read from, respectively the first memory
circuit, which signal combination is applied to an input combination 43 of this memory
circuit or is to be taken off from an output combination 45 thereof.
[0015] An input combination 47 of the synchronizing circuit 7 receives from a third counting
circuit 49, whose counting signal input is connected to an output 51 of a second pulse
generator 53 and to a clock signal input 55 of a second memory circuit 57 information
about the position in the second memory circuit 57 of a signal combination applied
to an input combination 59 or to be taken from an output combination 61 thereof.
[0016] The output combination 61 of the second memory circuit 57 applies a video signal
to be displayed to an input combination 63 of a display portion 65. A horizontal or
vertical synchronizing signal, respectively received from an output 71 or 73, respectively
of the synchronizing circuit 7 is applied to an input 67 or 69, respectively of the
display portion. As a result thereof, the scanning of the picture display portion
is coupled to the scanning of the second memory circuit 57.
[0017] In addition, the output 51 of the second pulse generator 53 is connected to an input
75 of the change-over circuit 37, an input 77 of which is connected to an output 79
of a third pulse generator 81, an input 83 to the output 23 of the first pulse generator
25 and an input 85 via a divide-by-three frequency divider 87 also to the output 23
of the first pulse generator 25.
[0018] The change-over circuit 37 is controlled by a signal combination applied to its input
combination 89, which signal combination is received from an output combination 91
of the synchronizing circuit 7.
[0019] In addition, the synchronizing circuit 7 has an output 93 which applies to an input
95 of a change-over switch 97 a signal which can move this change-over switch 93 to
the position shown or to the position not shown, and an output 99 which applies to
an input 101 of a change-over switch 103 a signal which can adjust this change-over
switch 103 to the position shown or to the position not shown.
[0020] The change-over switch 97 can connect the input 43 of the first memory circuit 41
to its output 45 or to the output 9 of the receiving portion 1. The change-over switch
103 can connect the input 59 of the second memory circuit 57 to its output 61 or to
the output 45 of the first memory circuit 41.
[0021] The memory circuits 41 and 57 are of a serial type, such as, for example, bucket-brigade
memories or charge-coupled devices. The signals to be processed thereby are assumed
to be digital signals. If the memories are not written-in, as when the change-over
switches 97,103 and of the change-over circuit 37 are in the positions shown, in which
the input 83 is connected to the output 35, the information circulates in the memories.
[0022] The first, second and third counting circuits 27, 33, 49 may be identical.
[0023] If after tuning the receiver to a new frequency the control actions of the receiver
have settled, the change-over circuit 37 position is changed by the synchronizing
circuit 7, as a result of which its input 77 is connected to the output 35 and the
clock signal from the third pulse generator 81 is applied to the first memory circuit
41 and to the second counting circuit 33. The frequency of this clock signal differs
from the frequency of the signal supplied by the first pulse generator 25, so that
the first memory circuit 41 and the second counting circuit 33 are then no longer
synchronous with the scan in the received television signal.
[0024] When the counting position of the second counting circuit 33 differs by a given amount
from the position of the first counting circuit 27, the synchronizing circuit 7 connects
the output 35 of the change-over circuit 37 to the input 83, so that the two counting
circuits are supplied with the same counting signal and the position of the second
counting circuit 33 continues to differ always by the said amount from the position
of the first counting circuit 27. This amount depends on the position the sub-picture
information to be written into the first memory circuit 41 must occupy in the composite
picture.
[0025] At the next vertical synchronizing pulse at the input 17 of the synchronizing circuit
7 this synchronizing circuit connects the input 85 of the change-over circuit 37 to
the output 35 thereof and the change-over switch 97 is adjusted to the position not
shown. As a result thereof, the video signal from the transmission which has been
tuned to is written in the correct sub-picture position in the first memory circuit
41. This writing operation is effected at one third of the frequency of the pulse
generator 25 and, in addition, every time following a horizontal deflection period
has been written-in, no writing operation is effected during two horizontal deflection
periods, so that the information of a sub-picture occupies only one-ninth of the storage
capacity of the memory circuit and, consequently, nine sub-pictures can be displayed
in the composite picture. It will be obvious that this number is optional.
[0026] If no vertical synchronizing pulse were to occur because no transmission is received,
a final-position signal from the first counting circuit 27 is then used as a starting
signal for the writing operation. In both cases this final-position signal also ends
the writing operation, as a result of which the input 83 of the change-over circuit
37 is again connected to the output 35 and the change-over switch 97 is again adjusted
to the position shown, so that, controlled by one third of the frequency of the pulse
generator 25 the information in the memory circuit 41 circulates up to the beginning
of the next horizontal deflection period to be written-in, so that it can again be
written into the proper position.
[0027] Thereafter the next frequency is tuned to by the synchronizing circuit 7 and the
synchronizing and writing cycle is repeated.
[0028] This happens nine times until all the sub-picture positions in the first memory circuit
41 have been filled.
[0029] Then the first memory circuit 41 is synchronized with the second memory circuit on
account of the fact that the synchronizing circuit 7 connects the input 77 of the
change-over circuit 37 to the output 35 until the positions of the second and third
counting circuit 33 and 49, respectively, are equal, whereafter the input 75 of the
change-over circuit is connected to the output 35. At the start of a counting cycle
of the third counting circuit 49 the change-over switch 103 is then adjusted to the
position not shown, until the end of that counting cycle. The nine items of sub-picture
information contained in the first memory circuit are then transferred to the second
memory circuit 57 and displayed during the next counting cycles, the change-over switch
103 being again in the position shown.
[0030] The displayed composite picture now only shows a change once in each tuning cycle
and produces a much more restful impression than for the case when a second memory
circuit is not used.
[0031] Although memory circuits of the serial type are used in the embodiment described,
it will be obvious that if so desired other types of memory circuits may alternatively
be used.
[0032] It will further be obvious that if so desired the displayed information may be simultaneously
changed in only a portion of the composite picture with a group of sub-pictures associated
with a group of transmissions.
[0033] The sequence in which different transmission frequencies are tuned to in a tuning
cycle may if so desired be chosen such that the sequence of the sub-pictures corresponds,
for example, to an array of switches in a program selection device.
[0034] It is further possible, for example, when a program selection device makes it possible
to tune to a greater number of transmitter frequencies than the maximum number of
sub-pictures possible in the composite picture, to periodically cause a shift of the
sub-pictures, as a result of which a then unoccupied portion of the composite picture
may be occupied by sub-pictures associated with further transmission frequencies.
1. Fernsehempfänger mit einer Schaltungsanordnung (1) zur sequentiellen Abstimmung
des Empfängers auf verschiedene Frequenzen und zur Wiedergabe eines zusammengestellten
Bildes, dessen Unterbilder Bildern entsprechen, die von auf den genannten verschiedenen
Frequenzen empfangenen Sendern ausgestrahlt werden, mit einer Speicherschaltung (41)
zum Speichern der Unterbildinformation, dadurch gekennzeichnet, dass der Empfänger
eine mit der erstgenannten Speicherschaltung koppelbare zweite Speicherschaltung aufweist
zum aus der ersten Speicherschaltung Übernehmen der bei der sequentiellen Abstimmung
erhaltenen Unterbildinformationen einer Gruppe von Sendern und zum auf derartige Weise
aus der zweiten Speicherschaltung (57) Wiedergeben einer dieser Gruppe von Sendern
zugeordneten Gruppe von Unterbildern, dass bei einer neuen sequentiellen Abstimmung
des Empfängers auf verschiedene Frequenzen diese Gruppe von Unterbildern in einem
zusammengestellten Bild gleichzeitig den Bildinhalt wechseln kann, so dass eine Übersicht
von Stand-Unterbildern erhalten wird.
2. Fernsehempfänger nach Anspruch 1, dadurch gekennzeichnet, dass dieser eine erste
mit einem empfangenen Signal synchronisierbare von einem ersten Impulsgenerator (25)
gesteuerte Zählerschaltung (27), eine zweite mit der ersten Speicherschaltung (41)
synchronisierte Zählerschaltung (33) und eine dritte mit der Bildwiedergabeanordnung
(65) synchronisierte, von einem zweiten Impulsgenerator (53) gesteuerte Zählerschaltung
(49) aufweist, wobei die zweite Zählerschaltung (33) mit Hilfe eines Umschaltkreises
(37) mit der ersten (27) oder der dritten Zählerschaltung (49) oder mit einem dritten
Impulsgenerator (81) koppelbar ist.
1. Récepteur de télévision comprenant un circuit (1) pour accorder le récepteur séquentielle-
ment sur différentes fréquences et pour afficher une image composite comprenant un
groupe de sous-images qui correspondent à des images émises par des émetteurs reçus
à ces diverses fréquences, le récepteur comprenant un circuit de mémoire (41) destiné
à stocker de l'information de sous-image, caractérisé en ce qu'il comprend un second
circuit de mémoire (57) qui peut être couplé au circuit de mémoire cité en premier
lieu (41) pour acquérir du circuit de mémoire cité en premier lieu l'information de
sous-image d'un groupe d'émissions, cette information de sous-image étant obtenue
pendant l'opération d'accord séquentiel, et pour afficher le groupe de sous-images
associé au groupe d'émissions à partir du second circuit de mémoire (57) d'une manière
telle que si un autre accord séquentiel du récepteur sur différentes fréquences, est
fait, ces groupes de sous-images dans une image composite puissent simultanément modifier
leur contenu d'image de telle sorte que l'on obtienne un aperçu de sous-images immobiles.
2. Récepteur de télévision suivant la revendication 1, caractérisé en ce qu'il comprend
un premier circuit de comptage (27) qui peut être synchronisé avec un signal reçu
et qui est commandé par un premier générateur d'impulsions (25), un deuxième circuit
de comptage (33) qui est synchronisé avec le premier circuit de mémoire (41) et un
troisième circuit de comptage (49) qui est synchronisé avec un dispositif d'affichage
d'images (65) et commandé par un second générateur d'impulsions (53), le deuxième
circuit de comptage (33) se prêtant à un couplage au premier (27) ou au troisième
(49) circuit de comptage ou à un troisième générateur d'impulsions (81) au moyen d'un
circuit de commutation (37).